I let my family members use my pc over rdp to play their flash-based games as their laptops overheat if they use them directly. I have it setup so I can use the pc at the same time as them. The pc has a quad core cpu and I would like to be able to assign one of those cores to the user logged in via RDP so that the other 3 cores are left alone. Is this possible?

This is not a simple solution but the best way to completely split the computer in to two (ore more) computers using VM (Virtual machine) software. This will solve your problem might solve future related issues as well (Junk, viruses...)

With VM installed you can choose how much CPU processing time each computer will get. This selection also works for other resources like memory, disk space, network bandwidth...

If you choose to do this, better make sure that your CPU supports Virtualization.

There are a number of things here.
Simplest solution would be to get it working on the laptop would it not?

Perhaps there is a problem with the laptop hardware, the fan?

You could try underclocking the laptop to reduce the running temperature.

If you're set on the RDP idea you could try:

reducing the process priority for rdp in the task manager. (I don't have windows 7, so I'm unsure whether this runs as a seperate process.) I think this should have a similar effect to what you're after. If rdp is running as a service, there probably is a way to reduce it's priority, but it isn't as straight forward I would imagine.

you could also try changing the process affinity in the task manager, I think using this you could assign rdp to exactly one core, but, again, it depends on whether rdp is a service as to how easy it would be to do this.

The laptop in question is old and underpowerd. It already runs really slowly so underclocking it would probably not be an option. I'll try to find the rdp service's proces and set the afinity on that though, thanks for that suggestion!
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Dean WardFeb 27 '11 at 13:19

found the process hosting the service and set it's afinity to a single core but the game's process still ran on other cores. Looks like this is going to be a no starter! thanks anyway.
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Dean WardFeb 27 '11 at 13:27